The super conductor wire is used on super conductor magnets, power transmission lines, and super conductor electric power system. The super conductivity of the high temperature super conductor can be utilized by using the cheap liquified nitrogen owing to its high threshold transition temperature unlike the conventional super conductors.
However, the high temperature superconductor has a high brittleness, and therefore, cannot be formed into wires. Therefore, it has been proposed that a metal having a large ductility and a large elongation be used so as to form into a composite wire.
Based on this method, Sumitomo Electric Company of Japan was successful in manufacturing a silver/BiSrCaCuO composite super conductor which has a threshold current density characteristics of 40,000 A/cm.sup.2 within liquified nitrogen.
Their method was such that a calcinated super conductor powder having a composition of (Pb,Bi).sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 was filled into a silver tube, and then, was drawn into a wire. Then the wire was subjected to repeated rollings and heat treatments, and thus, a super conductor was obtained in which the thickness and the width were small, and the current density was high, and in which the super conductor grains were oriented in one direction.
However, in this method, first there has to be formed a tube, and, in the process of forming such a tube, foreign materials can be intruded. Further, it is difficult to adjust the density of the super conductor powders, and the shape of the super conductor which is filled into the tube cannot be adjusted.